1. Field of the Invention
The present invention relates to an electronic apparatus having a cooling fan and a detachable air filter and, more particularly, when the air filter is attached to the electronic apparatus, or when the air filter is not attached to the electronic apparatus, the electronic apparatus according to the invention controls the cooling fan operating according to the same function of speed versus temperature, and cools the electronic apparatus effectively.
2. Description of the Prior Art
Present electronic apparatuses such as projectors, rear-projection TV sets, CD-ROM drives, and computers, have interior components generating heat during operation. Therefore, these electronic apparatuses all need to be equipped with cooling fans to cool its interior.
For optimizing the cooling performance inside the electronic apparatus, certain electronic apparatuses equipping with cooling fans store functions of fan speed versus temperature, and sense interior temperatures. The electronic apparatuses adjust speeds of their cooling fans according to the sensed interior temperatures and the functions of fan speed versus temperature.
Since the electronic apparatus is in the environment with serious air pollution, for preventing the pollutants from entering the interior of the electronic apparatus to damage its interior components, most of aforesaid electronic apparatuses needing cooling fans also have additional air filters attached to inlets of their casings for stopping the pollutants in the air from entering the interior of the electronic apparatuses. However, the attached air filter would be an obstruction for the airflow flowing into the electronic apparatus. If the original function of fan speed versus temperature is used, the airflow generated by the fan would be not insufficient for cooling the interior of the electronic apparatus, and the electronic apparatus would overheat and be breakdown. Electronic apparatuses equipped with air filters mostly use alternative functions of fan speed versus temperature for effectively cooling the interior of the electronic apparatus. However, such implementation needs memories with more storage capacity and designs of switching to different functions of fan speed versus temperature.
Accordingly, a scope of the invention is to provide an electronic apparatus having a cooling fan and a detachable air filter, and when the air filter is attached to the electronic apparatus, or when the air filter is not attached to the electronic apparatus, the electronic apparatus according to the invention controls the cooling fan operating according to the same function of speed versus temperature, and cools the electronic apparatus effectively